Substituted silylacetylene polymers have been shown to exhibit desriable permeability and separation properties for various liquid and/or gas mixtures. Various methods have been disclosed for polymerizing various substituted silylacetylene monomers to form the corresponding polymers. U.K. Patent Application No. 2135319A discloses a polymer formed by polymerizing one or more 1-monoalkyl(C.sub.1-12)dimethylsilyl-propynes. The polymerization is carried out at a temperature range of 30.degree. C.-100.degree. C. for 12-36 hours, typically in the presence of an organic solvent used in an amount providing a monomer concentration of 0.1 to 5 mole/l. The reaction is catalyzed by one or more compounds, including halides, of transition metals of Group V of the Periodic Table, optionally in combination with one or more organo-aluminum compounds as co-catalyst. The catalyst concentration is 0.01-20 mole %, and preferably 0.5-5 mole %.
Toshio Masuda, et al. in an article entitled "Polymerization of 1-(trimethylsilyl)-1-propyne by Halides of Niobium (V) and Tantalum (V) and Polymer Properties", Macromolecules 1985, 18, 841, 845, teaches polymerizing 1-(trimethylsilyl)-1-propyne using catalysts comprising pentahalides of niobium and tantalum to give a high molecular weight polymer. The effects of solvents, temperature, and monomer and catalyst concentration on the resulting molecular weights of the polymers were studied. It was reported that the molecular weight, both weight and number average as measured by gel permeation chromatography for the resulting polymer, was typically high; e.g. up to 1.times.10.sup.6.
Toshio Masuda, et al. "Synthesis of High Polymers from Disubstituted Acetylenes using Halides of Niobium (V) and Tantalum (V) as Catalysts" J. Chem. Soc., Chem. Commun., 1297-98 (1982), teach polymerizing Oct-3-yne and 1-phenylprop-1-yne using halides of Nb and Ta, to product white soluble polymers whose weight-average molecular weights exceed one million.
Takamizawa, et al., U.S. Pat. No. 4,567,245 discloses a copolymer obtained by the copolymerization of 1-trimethylsilyl-1-propyne and 1-(1,1,3,3-tetramethyl-1,3-disilabutyl)-1-propyne in a molar ratio of 30:70 to 95:5 having a number-average molecular weight of at least 1.times.10.sup.4. The copolymerization is carried out in an organic solvent in a temperature range from 30.degree. C. to 130.degree. C. in the presence of a polymerization catalyst such as WCl.sub.6, NbCl.sub.5, or TaCl.sub.5.
Langsam, U.S. Pat. No. 4,657,564 discloses a membrane formed from a poly(trialkylsilylacetylene) polymer. The polymer is formed by conventional polymerization methods, such as by polymerizing the monomer units in an organic solvent using a catalyst such as TaCl.sub.5, MoCl.sub.5, NbCl.sub.5, and the like.